Abstract
An apparatus comprises a test signal generator (401) which generates an ultrasonic test signal by modulating an audio band test signal on an ultrasonic signal. The ultrasonic test signal is radiated from a parametric loudspeaker (403) and is demodulated by non-linearities in the air. A reflected audio signal may arise from reflections of an object, such as a wall. An audio band sensor (405) generates an audio band captured signal which comprises the demodulated reflected audio band signal. A distance circuit (407) then generates a distance estimate for the distance from the parametric loudspeaker (403) to the object in response to a comparison of the audio band captured signal and the audio band test signal. Specifically two signals may be correlated to determine a delay corresponding to the full path length.; Based on the distance estimates an audio environment may be estimated and a sound system may be adapted accordingly.
Original language | English |
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Patent number | US8811119 (B2) |
Priority date | 20/05/10 |
Publication status | Published - 19 Aug 2014 |
Bibliographical note
Also published as:EP2572212 (A1)
US2013064042 (A1)